Identify which balance gets a new rate
A cash-out refinance replaces an existing mortgage with a new, larger loan and releases eligible net proceeds after payoffs and costs. A second mortgage adds a separate loan or line while the first mortgage remains. The central comparison is therefore not just the two new rates. It is the cost of financing the entire replacement balance versus keeping the first mortgage and financing the additional amount separately.
Build an equal-cash comparison
Ask both options to deliver the same usable cash after closing. A quote with a larger loan but higher fees may leave less cash than expected. For a second lien, add the existing first payment and the new payment. For a refinance, compare the new payment with that combined total, while also comparing the remaining term and payoff schedule. Include mortgage insurance, where relevant, and any change to how taxes and insurance are collected.
Use a balanced example
Consider a hypothetical owner with a substantial low-rate first mortgage who needs a relatively small additional amount. Repricing the entire first balance could cost more than taking a higher-rate second lien on the smaller amount. For another owner with an expensive existing first mortgage, consolidation into one new loan could be competitive. Neither pattern is universal. Calculate costs using actual balances, written offers and a realistic period before selling or refinancing.
Check future flexibility
A second lien adds another obligation to address if you later refinance or sell. A HELOC can also change payment with its balance and rate terms. A cash-out refinance may restart a long repayment period unless you choose or follow a shorter schedule. Ask what the balances would be at your expected exit date and whether a prepayment provision applies. Choose the structure that supports the purpose of the borrowing and leaves room for adverse changes, not simply the option with the smallest first payment.
Keep the use of proceeds specific
Separate necessary expenses from optional projects before determining the requested cash amount. Borrowing more because the payment appears manageable increases the balance you must repay and can change loan pricing. Ask for a smaller-cash alternative as well as the full request. Compare how each choice changes monthly obligations and the equity left in the property. A clear use-of-funds plan makes it easier to decide whether preserving the existing first loan, replacing it or postponing part of the spending best fits your priorities.
Common questions
Should I always keep a low-rate first mortgage?
It is an important advantage to measure, but the right comparison also includes the second loan's costs, payments, term and the amount of cash needed.
Is cash-out money income?
It is borrowed money that must be repaid. Discuss tax treatment and any interest deduction with a qualified tax adviser for your circumstances.
Sources & further reading
General educational information. Our editorial standards, ownership and AI-assistance disclosure.